Device for locking strowger switches in place



K. G. KAISER 2,740,528

DEVICE FOR LOCKING STROWGER SWITCHES IN PLACE April 3, 1956 2 Sheets-Sheet 1 Filed July 8, 1954 INVENTOR. KENNETH G. KAISER BY m ATTY.

April 3, 1956 K. G. KAISER DEVICE FOR LOCKING STROWGER SWITCHES IN PLACE Filed July 8, 1954 2 Sheets-Sheet 2 ATTY.

DEVICE FOR LOCKlN G STROWGER SWITCHES IN PLACE Kenneth G. Kaiser, Lombard, 111., assignor to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application July S, 1954, Serial No. 442,135 Claims. (Cl. 211-4) This invention relates generally to a locking device and more particularly to a device for securely fastening apparatus units to a shelf type frame.

This device as hereinafter described is more specifically adapted for use with apparatus units such as telephone switches of the Strowger automatic type and their associated shelf type frames.

An object of this invention is to provide a simple method for locking such apparatus units to their shelf type frames.

Another object of this invention is to provide a device for securely fastening apparatus units which are gravity mounted by means of pin and slot arrangement.

A feature of this invention is in the provision of a flat bar loosely connected to the top angle iron of a shelf on a mounting frame and slidably adjustable to extend over the top of the apparatus units to prevent any vertical displacement of the units.

Another feature of the invention resides in the simple structure of the elements of the device thereby providing for inexpensive fabrication, simple installation and easy operation.

This invention also features a device which is easily adapted for use with existing mounting units.

The above and other objects and features of the invention will be apparent from a perusal of the following specification and the accompanying drawings in which:

Fig. l is a perspective view of the locking device used with mounting frames for telephone apparatus and showing telephone switches in their mounted positions.

Fig. 2 is the perspective view of the locking bar member.

Fig. 3 is a front elevational view illustrating a shelf type mounting frame and its associated locking device for a shelf of several switches.

Fig. 4 is an enlarged sectional view taken along line AA of Fig. 3 depicting the locking device in its locking position.

Fig. 5 is a sectional View similar to Fig. 4 showing the locking device in its open position.

The present illustration is the preferred embodiment but it is to be understood that changes can be made in the present embodiment by one skilled in the art without departing from the true spirit and scope of this invention.

A short description of the invention will now follow:

In existing automatic telephone exchanges the switch units are customarily mounted in rows on a so-called shelf or frame. This frame is attached in the exchange to a pair of uprights which may support a vertical series of shelves or frames. Each shelf is constructed of horizontal angle irons having a series of vertical guide bars horizontally spaced apart along the frame and having pins on either side thereof as shown in Fig. 3. The switch units and their covers have pairs of L-shaped slots on the side thereof to permit each unit to be slid over the pins in the bars on either side thereof and then lowered so that the pins enter the vertical portion of the L-shaped slots. In shipping or moving, the switches have a tendency to become dislodgedfrom their mounting pinsand my locking device is designed to hold all the switches mounted on any one framesecurely in place.

Generally, this embodiment will be a flat metal bar 6 as shown in Fig. 2 made either of a strong metal or plastic, but for example we will suppose and prefer it to be made of steel. This bar will be loosely fastened to the top angle iron 1 of a mounting frame such as described above. The bar 6 is provided with two slotted holes 8 neareach end for the protrusion of two small bolts 14 securely fastened through a mounting angle 4, top angle 1 and through the slot 8 to beengaged by a wing nut 7. It is to be understood that only two slots have been illustrated for example but more could be added over long spans to more fully secure this lock bar 6. The lock bat-.6 has projections 9 at each end bent upward at an angle from its main portion. The purpose of the projections 9 is for grasping the lock bar 6 with the fingers to either shift the bar 6 or remove it from its location. This will become apparent in the ensuing disclosure.

The guide bars 2 have been modified asshown in Figs. 4 and 5 and each has a slot 12 cut out to engage the lock bar 6 when the lock bar 6 is shifted into its forward or locking position.

To describe in detail the operation of the instant invention reference is made first to Fig. 3. it will be,,,assumed that looking bar 6 has been loosely fastened to a horizontal top shelf angle 1. Horizontal top shelf angle 1 rigidly supports a plurality of vertical guide bars 2 near one end thereof and the bottom horizontal shelfangle 1t rigidly supports the vertical guide bars 2 near the other end thereof. The top and bottom angles 1 and ;10, are securely fastened to two mounting angles 4 and 11 .by any means such as the bolts 16 (Figs. 3, .4 and 5). Attached to the guide bars 2 are horizontal pins 5 securely fastened near both ends of the guide 'barsZ and projecting outward from either side thereof.

Reference is made now to Fig. 1 where switches 13 and switch covers 15 are shown leach attachedbymeans of pins 5 and slots 3 between two guide bars 2. Switches 13 and covers 15 have notches 3 to engage pins 5 upon being guided downward between two guide bars 2 as shown in Figs. 4 and 5. We will assume that the lock bar 6 is in its open or back position to allow the switches 13 and covers 15 to enter downward along the guide bars 2. The switches 13 and covers 15 could also have been inserted before the lock bar was even attached to the top shelf angle.

Attention is now called to the enlarged sectional views of Figs. 4 and 5 which are taken along line AA of Fig. 3 depicting the open and locking position of lock bar 6. It will be assumed that switches 13 and covers 15 have been inserted along the guide bars 2 and hooked on pins 5 by means of slots 3. It will be noticed in Fig. 5 that when the lock bar 6 is in its extreme open position it is flush with the front edge of the top shelf angle .l, and lock bar 6 can be locked in this position by tightening the wing nuts 7. After all the switches have been inserted as desired, wing nuts 7 are loosened and by grasping the projections 9 of the lock bar 6 with the fingers lock bar 6 is moved forward into the slots 12 of the modified guide bars 2 and lock bar 6 therefor will also overlap the covers 15 and switches 13 (Fig. 4). After the insertion of the lock bar 6 into the slots 12 of the guide bars 2 the wing nuts 7 will be tightened to hold the loci: bar 6 in look position. When in this look position the lock bar 6 will prevent any upward jarring of the switches 13 and prevent any dislodgement thereof. It will thus be seen that the lock bar 6 when in closed or locked position holds all the plurality of switches 13 on the shelf of the mounting frame in place. It can easily be seen that whenever switches are added or removed, all that is required is to loosen the wing nuts 7 and shift the lock bar 6 to its open position. The lock bar 6 when in its open or .back position is overlapped somewhat by the tops of the notches 12 of the guide bars 2 (Fig. 5) and when the bolts 14 are protruding through the slots 8 the lock bar 6 is prevented from being dislodged from its location even when the wing nuts 7 are removed, and thus will prevent the lock bar 6 from falling down and damaging mounted apparatus. In order to remove the lock bar 6 from its location the bolt 14 will have to be unscrewed from its secured position in the threaded holes of top mounting angle 4 and top shelf angle 1 so that bolts 14 are completely withdrawn from the slots 8 at each end of the lock bar 6.

Having described my invention what I consider new and desire to have protected by Letters Patent is:

1. In a locking device for holding switches in place on a mounting means, said means having a series of guide bars for guiding automatic type switches into position on said means, a series of automatic switches each mounted between certain of said guide bars, each of said guide bars having a notch cut out near the upper rear portion of said guide bar, said device including a lock bar slidable back and forth between two positions and engaging the tops of said switches and said notches for securing said automatic type switches to said mounting means when in one position, said notches overlapping said lock bar when engaged with or disengaged from said switches in either position.

2. A locking device for securing a plurality of switching units in place on a mounting frame, comprising a long flat bar extending over a plurality of switches mounted on the frame, a series of threaded studs projecting upward from the frame, a series of slotted holes in the bar through which said studs project, said bar movable back and forth by means of said slotted holes on said studs into an open and locked position, a nut for each stud for locking said bar in either position, said bar engaging the upper section of said switches to lock them in position when the bar is moved to its lock position.

3. In a locking device as claimed in claim 2 in which the mounting frame includes a plurality of notches, said flat bar having projections extending at each end, said projections acting as handles, whereby said bar may be shifted to engage said notches, said bar also movable by said handles to disengage said notches.

4. A locking device for holding a switch of the automatic type in place, a pair of guide bars, said pair of guide bars supporting the switch, said guide bars connected vertically to two horizontal mounting means comprising a top angle iron, a locking bar device loosely connected to the top angle iron of the mounting means, two slotted holes cut out near each end of said locking bar device for the protrusion of two studs, said two studs attached through said top mounting means and top angle to protrude through said two slotted holes, said locking bar device having a projection at each end, said pair of guide bars each having a notch cutout near the rear top, said locking bar device shifted by means of said projection to engage each notch of the said pair of guide bars, said locking bar device overlapping said switch when said locking device engages each notch of the pair of guide bars, a fastening means to engage said studs, said fastening means tightened to fasten said locking bar device to said mounting means to prevent said locking bar device from further movement, said locking device when overlapping said switch prevents said switch from vertical displacement.

5. A locking device for holding a series of apparatus units in place on a mounting frame on which they are supported by means of a series of bayonet joints, said device comprising a locking bar common to all of said units, and slidably mounted on the frame near the upper edge of said units, said bar slidable to one position to permit mounting of the units by means of said joints and slidable to another position, after the units are mounted, to lock all of the units in place and prevent disengagement of said joints, said bar slidable by means of a series of slots slidable on a series of studs projecting from the frame, and having means for securing the bar rigidly in either position.

References Cited in the file of this patent UNITED STATES PATENTS Neir et a1 Nov. 1, 1932. 

